Country living - the dangers of knotweed

Feb 19, 2011 | Categories:

There is no doubt that owning a home in the country is an attractive proposition. Many of us are tempted to buy a fully refurbished rural residence, renovate an aging rustic abode, or even purchase land and build our very own palace in the country. However, if you are one of the 100,000 individuals who move to the countryside each year, it’s time to wise up to one of the potential perils of a rural house purchase.

With today’s hectic lifestyles many of us dream of getting away from it all and escaping to our very own slice of the countryside. Visions of rural cottages, isolated barn conversions, and secluded country piles ignite feelings of homely comforts, roaring fires and woodland gardens.

There is no doubt that owning a home in the country is an attractive proposition. Many of us are tempted to buy a fully refurbished rural residence, renovate an aging rustic abode, or even purchase land and build our very own palace in the country. However, if you are one of the 100,000 individuals who move to the countryside each year, it’s time to wise up to one of the potential perils of a rural house purchase.

Know the Knotweed dangers

If you are considering a countryside purchase it’s very important that you are aware of the prevalent form of vegetation growth called Japanese Knotweed. Whether you’re buying a large estate property, an area of land ripe for development, or a small getaway pad, Japanese Knotweed is a potential threat. If left untreated the plant can cause significant damage to building’s foundations or structure and can become extremely difficult, not to mention costly, to deal with. Some mortgage lenders have even been known to decline to lend on properties affected by the plant.

How to spot it

When viewing a countryside house or redevelopment site take a good look outside in and around property and the surrounding grounds. Japanese Knotweed has hollow green stems with either red or purple specs and can grow up to 3 meters tall. Its leaves are up to 12 cm long, green and shield shaped. Clusters of creamy flowers appear on the tips of most stems from August to October.

Don’t take any chances

Although Japanese knotweed is easily identified by the expert horticulturalists among us, unless you are a budding Alan Titchmarsh, the best advice is to get any potential property checked out by a professional surveyor. A full structural or buildings survey is an in-depth report providing information on the structure of a property, any defects, potential problems (including exposure to Japanese Knotweed) and advice on repair and treatment options. Countrywide employs fully qualified RICS registered Chartered Surveyors and are able to provide a survey in just 5 days. As with any property purchase it’s vital that you are fully aware of property’s condition before you purchase and the threat of knotweed is no different.

Dealing with the problem

If, after commissioning a survey, it is discovered that your dream property is affected by Japanese knotweed don’t panic! You may of course decide to abandon the purchase but most of us will be reluctant to be beaten by the forces of nature. If you decide to proceed with the purchase here’s what to do:

Firstly alert the vendor to the problem. Provide them with the findings from of your survey and suggest opening price negotiations. Alternatively ask your vendor to treat the Knotweed as part of your purchase conditions.

If the decision is made that you will deal with the Knotweed yourself once the property becomes yours, be sure to act quickly. Knotweed is highly prevalent and if left to grow untreated it could make the situation considerably worse in a short period of time.

Get out your gardening gloves! If the knotweed is tall and/or impenetrable then cut back the stems in winter when they have died. Be extremely careful and use a hand scythe to avoid spreading the stem fragments. Dispose of all material safely and responsibly by burning it on site, or at a licensed landfill site. This will allow effective spray contact with the emergent growth the following spring.

Spray new growth at least once a year, but ideally twice in spring and late summer/autumn, using a non-persistent, general-purpose herbicide e.g. Glyphosate. The best and most effective time to spray is late summer/autumn, when the plant is flowering and the foliage is conducting the most nutrients to the rhizome to build food reserves. Ensure reputable Japanese knotweed contractors are used and are licensed to carry out chemical control.

Japanese knotweed stems will die back in winter but chemical control usually takes a minimum of three years to totally eradicate this invasive plant. Therefore the knotweed must still be regarded as infective within that three year period, or whilst re-growth still occurs during spring.

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